Leeds Crown Court heard when Donald Denton claimed housing and council tax benefit in 2009 the former miner failed to mention he was in receipt of a pension from Prudential.
Later that same year he began working for a health care firm and also did not notify that change in his circumstances, Michael Jowett, prosecuting, told the court.
As a result of his omissions he was overpaid £29,072 in benefits to which he was not entitled.
Mehran Nassiri, representing Denton, said he realised he was wrong not to mention his employment and pension but put it to the back of his mind. He had already repaid £10,450 after receiving an inheritance.
Denton, 63, of Ledston Luck Cottages, Kippax was jailed for 30 weeks after admitting three charges of benefit fraud.
Mr Jowett told the court in a separate case Rosemary Robinson was overpaid £27,209 in benefits after she failed to disclose she was receiving a pension from Friend’s Life.
She told investigators she was angry other people “were getting everything” while she was having to live within her means. Ian Cook representing her said she “became trapped in her own lies”.
Robinson, 61, of Westover Close, Bramley, was jailed for 34 weeks after she admitted three charges of failing to disclose information.